1. Field of the Invention
The present invention relates to a scanner, a printer, a memory medium and an image processing method.
2. Related Background Art
As a result of recent improvement in the performance of the color image reading device utilizing CCD or the like (such device being hereinafter called color scanner) and of the color printer, there is increasing danger of forging or unlawful reproduction of an original of which reproduction is forbidden, such as a banknote or a valuable security document, by reading such original by the color scanner as the image data and printing such image data by the color printer. In order to prevent such forging, the color copying apparatus consisting of a color scanner and a color printer often incorporates a forgery preventing device which inhibits the copying operation by recognizing the original of which reproduction is forbidden.
However, the forgery preventing device employed in the color copying apparatus functions only in the copying operation, and, if the original forbidden for reproduction is once read by a color scanner, the obtained data can be outputted by a color copying apparatus or another color printer through a controller, so that the original is eventually forged.